Implantable medical devices having one or more fenestrations are well known in the art. For instance, fenestrated stent grafts are known for placement across the iliac arteries, by the aortic arch arteries and so on. The fenestrations may simply provide openings for side passage of blood passing through the main lumen of the stent graft, but are also known as couplings for side branches to the medical device.
A fenestrated medical device must be positioned accurately, not only in a longitudinal position in the vessel but also in the correct rotational position so that the or each fenestration is correctly aligned with its associated branch vessel or other feature. As such medical devices are more conveniently deployed endoluminally, it is necessary to be able to visualise the device through imaging during the deployment procedure. As the principal components of the device, typically stents and graft material, are not particularly visible under such imaging, it is common to provide on such devices radiopaque markers such as gold tabs or the like. Traditionally, such markers have been attached to the graft material, for instance by suturing.
It is also known to provide fenestrations with strengthening rings around the apertures in the graft material, such strengthening rings for instance being in the form of one of more turns of wire. A radiopaque marker may be provided on the strengthening ring.
Examples of prior art devices can be found, for example, in US-2011/0190868, WO-2010/030370, WO-95/21592, U.S. Pat. No. 5,653,743, US-2009/0157164, U.S. Pat. Nos. 6,524,335 and 5,824,042.
Known structures of fenestrated medical devices involve the provision of a multitude of components which require relatively involved assembly procedures.